The term allergic conjunctivitis describes the inflammation of the conjunctiva of the eye. The conjunctiva is the mucous membrane that overlies the eyeball.
What is allergic conjunctivitis?
The term allergic conjunctivitis describes the inflammation of the conjunctiva of the eye. Allergic conjunctivitis is common. It is estimated that circa 20 percent of the population is affected. Itching, reddened eyes, discharge from the nose and sneezing are some of the symptoms that plague sufferers of allergic conjunctivitis. The most common trigger is a pollen allergy. In treatment, anti-allergic eye drops are usually used.
Causes
Many substances can cause irritation of the conjunctiva. These include cosmetics, animal hair (cat allergy), and medications. Eye drops or ointments and the preservative solutions for contact lenses should also be considered as causes. Most often, however, conjunctivitis manifests itself as a result of an allergy to pollen. Here we also speak of seasonal allergic conjunctivitis and allergic rhinoconjunctivitis, because the symptoms occur depending on the season. Usually the nose is also affected. If the symptoms persist throughout the year, regardless of the season, it is called perennial allergic conjunctivitis. At the cellular level, the following processes lead to the inflammation: The allergen is dissolved in the tear film and migrates through the mucosal layers. When it encounters an inflammatory cell, the cell releases histamine. This is a messenger substance that causes further inflammatory cells to be attracted. The inflammatory event is reflected in the eye as redness, water retention and itching.
Symptoms, complaints, and signs
Allergic conjunctivitis is manifested by typical symptoms, such as itching and burning, red eyes and sticky eyes due to seeping secretions. Reddened eyes are the most obvious sign of the disease and usually occur on both sides. In the case of a pronounced conjunctivitis, the eyelids and parts of the face may also be reddened, always depending on the allergen. Accompanying these complaints, there is usually also a feeling of pressure on the eye, which increases when touched. The flow of tears is increased and there is more swelling in the area of the conjunctiva. Affected persons are photophobic and the eyes react sensitively to stimuli such as cold or heat. This can be accompanied by typical allergy symptoms such as sneezing and rhinitis. The respiratory tract can also be affected: breathing difficulties, coughing and expectoration occur. The above symptoms may be limited to one eye or occur on both sides. Occasionally, the inflammation occurs initially on one side only and then spreads to the other eye. The intensity of the symptoms depends on the extent of the conjunctivitis. The cause of allergic conjunctivitis also determines which symptoms occur and how severe they are.
Diagnosis and course
The diagnosis of allergic conjunctivitis can be made primarily on the basis of clinical symptoms. Other forms of conjunctivitis, dry eyes, and lid margin inflammation must be excluded. The most common symptom of allergic conjunctivitis is itching and a so-called chemosis. This is a massive swelling of the conjunctiva due to fluid retention. The fluid occurs because the vessels of the conjunctiva become more permeable due to the inflammatory processes. The eye then looks glassy and may protrude conspicuously from the orbit. Those affected also suffer from watery eyes and sneezing. In so-called spring catarrh, which often occurs in young men, growths may form on the inside of the eyelid. There may also be buildup on the conjunctiva.
Complications
Allergic conjunctivitis occurs as part of an allergic reaction. A possible consequence is a so-called superinfection. Due to the allergy, the immune system at the eye is weakened and thus pathogens can penetrate more easily and additionally infect the eye. This makes treatment much more difficult. In the course of the eye infection, in the worst case, a clouding of the cornea can occur, resulting in a severe impairment of vision. In the rarest cases, blindness of the affected person also occurs.The inflammation can also lead to the formation of scar tissue on the eye, which also results in clouding of the cornea. The scar tissue can also block the tear ducts and thus prevent moistening of the eye, which thus dries out. In addition, an allergic reaction also results in swelling of the airways. This typically leads to severe shortness of breath and difficulty in swallowing on the part of the affected person. The development of Quincke’s edema is also conceivable, whereby fluid accumulates in the deep layers of the skin, leading to even greater swelling. The worst case of an allergic reaction is anaphylactic shock, in which there is a sharp drop in blood pressure. This can be a life-threatening condition, as a result of which important organs no longer receive sufficient blood supply and can therefore fail.
When should you see a doctor?
The tearing, itching and burning associated with allergic conjunctivitis can sometimes be effectively relieved with cool compresses or artificial tears. These are available over-the-counter at any drugstore and can be stored in a cool place for extended periods of time. In this case, a visit to the doctor is not necessary. Persistent discomfort sometimes masks a more serious eye disease, which initially announces itself with symptoms similar to those of “red eye”. Thus, after six hours of unchanging complaints at the latest, an ophthalmological examination is inevitable. Allergic conjunctivitis is very unpleasant, especially for younger children. Since it is difficult to stop them from rubbing their eyes, there is a risk of bacteria entering or painful swelling of the conjunctiva. Children affected by allergic conjunctivitis should therefore always seek ophthalmological treatment. If patients of any age regularly suffer from conjunctivitis, an allergy test is a good idea. It is offered by ear, nose and throat specialists, dermatologists (skin specialists) as well as general practitioners. However, for an accurate diagnosis, a specialist training in allergology is essential.
Treatment and therapy
The primary treatment goal for conjunctivitis is to desensitize the conjunctiva. This is achieved with astringent eye drops. They alter the protein components of the conjunctiva. The use of antihistamines is also possible. They inhibit inflammatory cells from releasing histamine, which triggers the symptoms. Antihistamines are available as a component of tablets, juice or eye drops in pharmacy stores. Eye drops have the decisive advantage over the other preparations in that they act directly on the inflammatory process and the effect is felt after just a few minutes and usually lasts up to 12 hours. They are also commercially available as single doses and then usually contain no preservatives. Anti-allergic eye drops should be used without a contact lens, otherwise they may cause further irritation of the conjunctiva. Anti-allergic eye drops are applied to the eyes two to four times a day unless otherwise prescribed. One drop is placed in each eye. The duration of treatment with anti-allergic eye drops should be limited to two weeks in case of self-medication. If prescribed by a doctor, it is possible to use them for months. Redness and burning may occur as a side effect. In case of hypersensitivity, anti-allergic eye drops are contraindicated. Another possible group of drugs are mast cell stabilizers. These are preparations that directly prevent mast cells (inflammatory cells) from releasing histamine. Mast cell stabilizers can be administered as eye drops or orally as well. In cases of greater distress, short-term cortisone may also provide relief. However, preparations containing cortisone should be used very carefully. Prolonged use can lead to cataract (clouding of the lens) and glaucoma (increase in intraocular pressure). Occasionally, conjunctivitis is due to poor hygiene. Then it is the bacterial toxins that cause the inflammation. In this type of conjunctivitis, the use of antibiotics should be considered.
Outlook and prognosis
In this disease, severe discomfort occurs mainly in the eyes. Those affected suffer mainly from itchy and red eyes. However, scratching and rubbing the eyes usually only intensifies the itching.Without treatment, conjunctivitis also occurs. Patients suffer from severe pain directly in the eyes. The eyes themselves may water and in many cases are also sensitive to light. If not treated, this complaint can also lead to loss of vision or visual discomfort. Likewise, it is not uncommon for severe sneezing to occur. Also, the eye itself usually protrudes from the eye socket and may look unusual. Especially in children, this complaint can lead to bullying or teasing. The patient’s quality of life is reduced by all these symptoms. In most cases, the condition can be treated with the help of medication. Eye drops are also used in this process. The life expectancy of the patient is not limited. In suitable cases, cataract or glaucoma may still occur after treatment.
Prevention
For prevention, people who suffer from conjunctivitis more frequently should use allergy-tested cosmetics and avoid touching their eyes. Hands should be washed regularly to prevent bacterial infection.
Aftercare
Allergic conjunctivitis can flare up again and again if an allergen cannot be avoided consistently. Therefore, follow-up care refers not only to the symptoms that have occurred with this form of conjunctivitis. It also refers to measures with which an allergen can be avoided as best as possible. In addition, aftercare by an ophthalmologist is recommended after severe cases of allergic conjunctivitis. He will also inform about measures of individual aftercare. Family doctor and contact person are also professional contacts. Reddened and dry eyes are characteristics of the irritant state of allergic conjunctivitis. The sensitive conjunctiva of the eye must therefore be protected from further irritation as part of aftercare. This applies to harsh facial cleansers as well as makeup such as kohl, mascara, and eye shadow, or drops of sweat that may run into the eye during exercise. Moisturizing eye drops can be used in consultation with an ophthalmologist to specifically moisturize the eyes and consistently prevent further irritation. Aftercare for allergic conjunctivitis in terms of pollen avoidance includes washing hair before bed during pollen season, using pollen filters in the car, and cooling the eyes rather than rubbing them with fingers when itchy, thereby irritating them. Walks during pollen season are usually less allergenic in the evening hours.
What you can do yourself
Allergic conjunctivitis is a conjunctivitis of the eyes that usually has a good prognosis and where those affected can do a lot in everyday life to prevent or alleviate the classic symptoms. One of the prerequisites for this is the willingness of the patient to avoid the triggering allergen as far as possible. This applies to the pollen filter in the car and washing the hair at night in the case of pollen allergy, as well as to the avoidance of cosmetics in which the affected person is allergic to certain ingredients. All this can serve to limit the extent of allergic conjunctivitis in advance. In the event of an outbreak of conjunctivitis, there are also a number of things that the person affected can do to help it heal quickly. It is particularly important in this connection that the patient controls himself despite the sometimes strong itching and does not constantly rub his eyes with his fists. Wetting the irritated eye area with cold water or applying a cool compress can help. In consultation with the attending physician or ophthalmologist, special solutions can also be used to provide the eyes with moisture. They are ideal against the dryness of irritated eyes and in many cases also take away the feeling of having a grain of sand in the eye.
